Free Chemical Process Principles MCQs with Answers
2,710 Chemical Process Principles MCQs from Chemical Engineering, each with the correct answer and a written explanation of why it is correct. Free and unlimited, with no account needed.
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1761. During size reduction by a jaw crusher, the energy consumed decreases with the__________________?
- A. Decreasing size of product at constant size of feed
- B. Decreasing machine capacity
- C. Increasing size of feed at constant reduction ratio
- D. None of these
Explanation: At a fixed reduction ratio, increasing the feed size produces less new surface area per unit mass, so the specific energy requirement…
Correct answer: Increasing size of feed at constant reduction ratio- A. Abrasive
- B. Non-sticky
- C. Coarse
- D. Large quantity of very fine
Explanation: Wet sieving is preferred when the feed contains a large amount of very fine material, because liquid prevents fine particles from blinding…
Correct answer: Large quantity of very fine- A. 0.00184
- B. 0.0184
- C. 0.184
- D. 1.84
Explanation: Taggart's criterion uses the ratio of hourly tonnage to the square of the gape in centimetres.
Correct answer: 0.0184- A. 0.5
- B. 1.0
- C. 2.76
- D. 0.66
Explanation: The critical speed is calculated from the effective radius to the ball centre: N_c = [g/(4π²(R-r))]¹ᐟ².
Correct answer: 0.66- A. 6.35 kWh/ton
- B. 9.0 kWh/ton
- C. 18 kWh/ton
- D. 25.4 kWh/ton
Explanation: Bond's law gives energy proportional to 1/√P, so reducing the product size from 100 to 50 μm increases the energy by √(100/50) = 1.414.
Correct answer: 18 kWh/ton1766. _______________ mill is not used for grinding wheat into flour and for milling of cereals & other ?
- A. vegetable products.
- B. Buhrstone
- C. Pebble
- D. Attrition
- E. Roller
Explanation: Buhrstone, roller, and attrition mills are used for cereal and flour milling, whereas pebble mills are mainly used for fine grinding hard…
Correct answer: Pebble- A. Ball mill
- B. Gyratory crusher
- C. Tube mill
- D. Squirrel-cage disintegrator
Explanation: A gyratory crusher is a primary crusher designed for the preliminary breaking of large, hard rock.
Correct answer: Gyratory crusher- A. Crushing rolls
- B. Ball mill
- C. Buhrstone mill
- D. Hammer mill
Explanation: Buhrstone mills are traditionally and extensively used for grinding cereals, grains, spices, pigments, sawdust, and cork.
Correct answer: Buhrstone mill- A. Semi-plastic clay
- B. Fuller's earth
- C. Vermiculite
- D. Diatomaceous earth
Explanation: Diatomaceous earth, also called kieselguhr, is the most commonly used filter aid because its porous, low-density particles form a highly…
Correct answer: Diatomaceous earth- A. Blending of immiscible liquids
- B. Dispersing gas in liquid
- C. Dispersing immiscible liquid in form of emulsion
- D. Suspending solid particles
Explanation: Agitation can disperse one immiscible liquid into another to form an emulsion, suspend solids, and disperse gas in liquid.
Correct answer: Blending of immiscible liquids- A. Have the same diameter
- B. Are rotated towards each other
- C. All A., B. and C.
- D. Run either at the same or different speeds
Explanation: A roll crusher uses two rolls of generally equal diameter rotating toward one another, and the rolls may run at equal or different speeds…
Correct answer: All A., B. and C.1772. In froth floatation, chemical agent added to cause air adherence is called___________________?
- A. Activator
- B. Frother
- C. Modifier
- D. Collector
Explanation: A collector makes the mineral surface hydrophobic so that mineral particles adhere to air bubbles.
Correct answer: Collector- A. Forged/cast steel
- B. Alloy steel
- C. Cast iron
- D. Lead
Explanation: Ball-mill media are commonly made from forged or cast steel, cast iron, or alloy steel because they must resist impact and abrasion.
Correct answer: Lead- A. Mixing highly viscous pastes
- B. Blending immiscible liquids
- C. Mixing liquids at very high temperature (> 250 °C)
- D. None of these
Explanation: A helical screw agitator produces strong axial movement and is suitable for highly viscous materials such as pastes.
Correct answer: Mixing highly viscous pastes- A. D
- B. D2.5
- C. 1/D
- D. 1/D2.5
Explanation: For a fixed ball load and operating condition, ball-mill power scales approximately with the 2.5 power of mill diameter, so power is…
Correct answer: D2.5- A. Calcite
- B. Fluorspar
- C. Cassiterite
- D. Quartz
Explanation: Cassiterite is tin oxide, SnO2, and is classified as a metallic ore because it is the principal source of tin.
Correct answer: Cassiterite1777. Fluid medium used in the classification technique of mineral beneficiation is_________________?
- A. Either A. or B.
- B. Water
- C. Air
- D. Neither A. nor B.
Explanation: Classification separates particles according to settling behaviour in a fluid, commonly water in wet classification or air in pneumatic…
Correct answer: Either A. or B.- A. Talc
- B. Coal
- C. Iron core
- D. Wheat
Explanation: A Bradford breaker is a rotary screen-type crusher widely used for coal, especially for breaking and sizing run-of-mine coal.
Correct answer: Coal- A. Banbury mixer
- B. Pug mill
- C. Impact wheels
- D. Kneader
Explanation: Impact wheels are used to disperse and blend light, fine dry powders such as insecticides.
Correct answer: Impact wheels- A. None of these
- B. Roll
- C. Vibratory
- D. Impact
Explanation: A cage mill breaks particles mainly by impact as rapidly moving bars strike them.
Correct answer: Impact